From Emergency Airworthiness Directive (AD) 2014-25-52

... due to blocked AOA probes, the flight control laws
order a continuous nose down pitch rate that, in a worst case scenario, cannot
be stopped with backward sidestick inputs, even in the full backward position. If
the Mach number increases during a nose down order, the AOA value of the
Alpha Prot will continue to decrease. As a result, the flight control laws will
continue to order a nose down pitch rate, even if the speed is above minimum
selectable speed, known as VLS.
This condition, if not corrected, could result in loss of control of the aeroplane....


AD – AFM Procedure
• If the Alpha Prot strip (black and amber) completely and permanently hides the VLS strip (amber) in a stabilized wings-level flight path (without an increase in the load factor):

Keep on one ADR.
Turn off two ADRs.

(emphasis mine)

Gesus: this reads a bit like Space Odyssey 2001 where Dave is deactivating HAL. :sad:

That goes without saying for anyone who is a professional pilot. Those who question it, really shouldn't be here ...

So to sum up .... I'm right. There IS insufficient bandwidth. :E

eabandit

would you rather spend 10 million on tracking or training for pilots to be safer?

you don't have all the money in the world to spend.

And quite frankly , every passenger has a choice on which airline to fly and votes with his pocketbook.

Not that a reservation agent will know, but simply find out. Does your airline, if the route is over significant , non radar covered , bodies of water have tracking?

IF NO, don't fly on them.



I know how I would run an airline and how to allocate resources. And looking back and saying: gee, if we had put gadgets on all the planes we wouldn't have to send out the 7th fleet to find things and think abouthow much money that would save.

It doesn't work that way.

Like others have said, it is obvious when people posting here are not professional pilots and it creates a situation where there is debate about things ( such as above) that there is no debate about between the pro's. It is a waste of space and moves the conversation further away from where it should be in a professional pilots forum.
If you are using 99% of your brain to try to make sense of what erroneous instrumentation is telling you while at the same time being affected by g forces, now is not the time to allocate 10% of your brain space to making a radio call.

Air Asia Indonesia Lost Contact from Surabaya to Singapore
 

Apparently I'll have to rephrase that. What's the point in reiterating "aviate, navigate, communicate" on a forum presumably used by pro's? Most likely it all went pear shaped at aviate for some reason and I'm fairly certain they knew what was next, only they never got to that step in this marvel that is aviation.

+1. Besides, you're still planning to fix whatever the problem is, so issuing a Mayday call is admitting defeat. And you may not know enough about the problem to verbalize it in the first place. This whole conversation is rather silly...

I've been addressing this very topic repeatedly today with my non-aviator friends. They simply cannot comprehend the difference between making a radio call containing dubious information - yielding zero result - and a call to 911/999 asking for assistance.

News flash, lurkers: "Ground, 8501, we've departed" will get you

no

help

at all.

"due to blocked AOA probes, the flight control laws " From Emergency Airworthiness Directive (AD) 2014-25-52

If this situation is not understood fairly fast, there will be not long time until you have lost full control.

This will depend on the training department, sending out a directive does not necessary mean that this is understood, how the aircraft will behave.

Of course there will be a combination of things colluding at similar time that will confuse the pilots.

Bad weather in combination with this, and the Swiss cheese model can be lined up step by step!

I experienced this scenario in the Sim without being aware of this, and it did not take long time before you sat there fat, dumb and happy, without a clue of what to do!

Because you get conflicting messages and you can not control the aircraft! The time it takes for this to develop is not very long, and before you know it you might be in an unrecoverable state!

That climb request to FL380 "to avoid weather" has been puzzling me.

(begin speculation)

Now I think the pilots were not overly concerned with the weather, before flying into a developing cell.

Consider, at the time, there were up to seven other planes nearby, including several flying just ahead and just behind QZ8501 on the same airway. According to media, none of the other pilots reported flying through strong turbulence or any other hazardous conditions.

It seems to me that QZ8501 was a routine flight. There was some weather ahead so they requested deviation to the left, like they've done hundreds of times before. From the radar picture you can see Emirates 409 had done the same just ahead. In fact, QZ8501 was joining the track UAE409 had left a few minutes before.

Then they requested climb to FL380 not due to "weather" per se, but because it was routine at this stage of the flight to climb higher (being lighter with less fuel). I've reviewed several other A320 flights on this route and it's not unusual to see flights go to FL360 or FL380 near this spot.

The routine aspect of this climb is what makes me think the crew was not overly concerned about the weather or the situation they were in. If they were seriously concerned, they would have deviated further first, not climb up at that point.

(I can see pilots climbing to better assess what's ahead, and maybe for a smoother ride, but I highly doubt a very experienced Captain from the tropics would try to out-climb a cumulonimbus.)

Yet the radar picture shows QZ8501 at FL363 and climbing (*). Perhaps control was already lost at this point. By deviating left, they inadvertently flew into a newly developing CB with very powerful updrafts. The plane is violently pushed up, nose very high, and quickly rolled to one side; groundspeed rapidly drops.

The pilots tried to recover from the unusual attitude and were not able to do so.

The plane did not "break up in flight", but flight control was lost. Perhaps the rudder or other control surfaces sheared. As the plane was plunging to the ground, below FL290, the ADS-B signal was lost due to line-of-sight distance from the nearest ground station at Pangkalan Bun.

The aircraft was largely intact when it impacted the ocean, perhaps steeply nose-down, creating few debris. The pilots tried to save the airplane all the way down.

(*) also note that ATC FLs are not actually physical altitudes but derived from Mode C pressure transmissions, which may be erroneous.

(end speculation)

This seems to be media speculation rather than fact. The official statement of events says that they dont know why he requested to climb:

source

From what I have been reading, they were initially maintaining 470 knots at FL320 and requested a course deviation and climb to FL380. They never responded to the clearance to climb to FL340 and they were probably out of control as they climbed through FL363 with a groundspeed of only 353 knots. (approx 333 knots TAS) (approx 180 knots IAS)

What was the time of the AirNav Indonesia Radar screen shot showing them climbing through FL363? I assume it was at approx 06:14-06:16 local.

Details from AirNav Indonesia (http://www.airnavindonesia.co.id):



The Aviation Herald Crash: Indonesia Asia A320 over Java Sea on Dec 28th 2014, aircraft went missing believed to have impacted waters

AirNav Indonesia Radar screen shot:

http://i2.photobucket.com/albums/y17...r.jpg~original

Chart showing 20 Knot tailwind

http://i.picresize.com/images/2014/12/28/zrxf.gif

Some pilots have been able to call ATC when their aircraft was doomed, the PSA 727 crash comes to mind as a good example. This was after the crew knew they had lost control of the aircraft and they had time to let the tower know. Every situation is different and every crew member is different, if you have time to let ATC know whats happening that's a good thing, but only after you have addressed the priorities as other members on this board have mentioned.

09:01:55 Captain (to Lindbergh tower) Tower, we're going down, this is PSA
09:01:57 Lindbergh tower OK, we'll call the equipment for you
09:01:58 Unknown Whoo!
09:01:58 ((Sound of stall warning))
09:01:59 Unknown Bob!
09:01:59 Captain (to Lindbergh tower) This is it, baby!

What about the FDR pinger/locator?
 

Has anyone got any updates/details about whether there are signals from the FDR pinger locator - seems to be ignored in this thread ?!

Does this A320 variety suffer at all from Ice Crystal Icing? Any operators have first or second hand experience of this on a A320 series?

I don't fly the bus so I may have the terminology wrong here, but in normal law, wouldn't the high angle of attack and high angle of bank protection prevent this from happening?

There's an EASA proposed AD (PAD 14-139 Date: 09 September 2014) which appears to potentially apply to all A320 series, but the critical factor appears to be which variety of probe is fitted. (The PAD does not specify what the replacement probe is to be, just what is to be removed and is no longer allowed; I seem to recall that at one time there was a suggestion that this was a "Thales/Sextant problem" and some operators were intentionally introducing "mixed" probe configurations (Goodrich mixed with Thales) as a kind of "insurance" again this being a design flaw, but I think there have been Goodrich incidents since, so that theory may have been discredited.

But perhaps a more important point is that practically all pitot probes are vulnerable to the ice crystal phenomenom; until very recently, nothing in the certification of probe addressed it at all, so any robustness one design might have had was as much luck as by design.

Simplistically, not necessarily.

The protections are pretty much fool proof against a pilot induced high aoa/low energy state being achieved - it just won't let you command the plane into trouble (again, simplistic) - but subject the aircraft to a massive external disturbance, and there's not a lot the FBW can do if the disturbance is too big. If full nose down elevator isn't enough to prevent an externally induced pitch up, the FBW is along for the ride, just like a crew of a conventionally controlled plane.

This is where we get the difference between "An airbus cannot be stalled" - which is kind of true, as it implies that this is a "commanded stall", and thus the FBW can simply prevent the pilot from causing the stall - and "An airbus cannot stall" which implies magic aerodynamics that work at 90 degrees AOA, and which neither Toulouse nor anyone else has the ability to create.

Quote:
Has anyone got any updates/details about whether there are signals from the FDR pinger locator - seems to be ignored in this thread ?!




Probably the plan is to wait for the weather to clear and hopefully have some debris spotted before the acoustic search is begun. At least the search should be fairly flexible because there is no need to stream several miles of cable just to get the fish down close to the bottom.
Still, finding the pinger in a shallow and heavily trafficked strait will not be easy.

I am in favour of reducing the stress and trauma on the thousands of relatives of missing passengers, who themselves are victims.
Apparently many hold out hope, even now, that their loved ones could be alive or injured.


A dozen $400 plbs and a few more eperbs distributed throughout the cabin would if nothing help those left behind come to a more speedy realisation of the prospects of survival of their loved ones.

The relience on one or two ruggedised expensive locator beacons to locate wreckage in water quickly has failed us in this regard.

So the likelyhood of lets say, one in twelve non ruggedised water activated epirbs suviving the chaotic nature of a crash and floating to the surface should now be considered.

A proactive carrier could provide a belt worn plb to cabin crew and stuff one in the survival pouch of every life raft.

A plb holstered above every exit door with instructions on its use in the seat back saftey card would also be a step forward.

In the eyes of the travelling public the aviation industry is making an ass of itself.

Not really ignored but only becoming relevant now with specialized ships capable of detecting them just arriving in the area.

The civilian 37.5 kHz Undewater Locator Beacon (ULB) has a very limited range, usually only about 3 nm, maybe a bit more if sea conditions are favorable.

Mind you, the search area is now over 50,000 square miles -- roughly the same size of Greece! So comparatively you'll almost have to be "on top" of an ULB to hear its ping.

Often ULBs are more useful in locating the "black boxes" after the general crash area has been found by other means (side-scan sonar, debris, oil slick, etc.)

Some military aircraft have low-frequency beacons (8 to 10 kHz) which can be detected from 5 to 10 miles; however, they are not yet standard on civilian aircraft.

The Java sea is shallow, so at least the helps in the logistics of hearing ULBs. (Although there is sometimes more interference in shallow water).

Re: timeline
 

A regular poster in another forum who works in some aspect of Indonesian aviation safety has stated that from his inside information, the plane went "from 32000 to 36300 and down again to 24000ft or so (in) just over a minute."

He hints that the people who have looked at the radar data believe that the plane must have broken up or lost control surfaces, quote: "it ain't a pretty picture".

mickjoebill,

Totally with you on that. 3 deployable EPIRBs which transmit GPS location on impact and or separation from aircraft in the water. One on each wingtip and one in the tail. Technology already available at your local marine supplies shop.

Sorry gents, those epirbs won't survive the crash in the first place. :ugh:

16000ft of vertical space in a little over a minute? Could it have been a descent to 34000, instead of 24000? I ask because it seems quite a feat to climb at 4000ft/min at that altitude anyway, much less do so and then drop 12000 feet afterwards in the same time span. Wouldn't it have to manage a 6000+ ft/min climb to FL360 just to have the time to free fall 12000 ft. (assuming a breakup, as stated)?

Those rates of climb would be no problem if caught in the updrafts of a large thunderstorm.

I hear where you are comming from, but neither you or I know this about any particular crash with 100% certainty.
Accidents are chaotic.
Installing a large number of devices hoping one will survive is not an unreasonable approach. I say this from a backgound of installing cameras in explosive environments, including three aircraft frames that were destroyed.

In any event if an aircraft so fitted goes missing without further contact it serves to reinforce the prospect that passenger survival is remote, which adresses the context of my original post relating to relatives of passengers and crew.

Sorry gents, those epirbs won't survive the crash in the first place.


It is amazing what items survive a crash and what does not - any cell/mobile phones working from MH17 after impact?


Those rates of climb would be no problem if caught in the updrafts of a large thunderstorm. Correct it only hurts when spat out of the cell.

Epirbs, ELTs etc...
 

While I understand the impulse to come up with a solution to the lost airliner problem, adding more portable ELTs isn't it. The more portable ELTs in the field, the more false alerts.

I believe the industry is heading toward an ejectable floating ELT similar to a distress buoy deployed by submarines, but that will take a couple of years worth of regulation, engineering and retrofitting. Even if the industry had started to get serious about this the day after MH370 there would have been no new beacons installed by now.

On mayday calls: what added information do you think the crew could have reasonably transmitted? The only advantage would have been a faster search, but that should have been almost instant anyway.

Of course every crash is different. In MH17 for example a lot of lightweight items were thrown out of the plane at altitude, fell at a relatively low terminal velocity, and hence survived.

How much impact forces can a typical EPIRB withstand? 100Gs? 200Gs?

Consider that an airplane hitting the ground at a "mere" 270 kts has an impact force of 3,400 Gs -- which is the basis for blackbox requirements.

I specifically asked survival of cell/mobile phones in on or outside MH17 for a reason. Most/many phones are u/s when falling more than 10 feet. many worked after MH17 to the point the death cert was not required to block the phones. As far as ELB/T g force survival on g force there are none but many/most are solid sate. And can withstand a lot (seems except aviation approved hand held ones). I don't know if more on an aircraft would help, but I know here if you wish to carry your own on an airline it is not permitted generally but can get a approval if wanted but about the same as carrying a firearm on an aircraft.

Maday call... or not?
 

Rather than a "Help me please because I'm helpless" call, I'm wondering if one of the ATCO's could let us know if there is a significant difference in initiation timing between an Uncertain Phase and Distress Phase of SAR both with and without a Mayday notification?
It would seem to me that a Mayday call (simultaneously notifying AND declaring an emergency exists) would remove any ambiguity that might possibly exist with observing (e.g. just the loss of txpdr return). In this case perhaps the crew did and the message failed to get out. We shall await the evidence.

The high water content ice which is normally associated with convective weather could have caused a engine flame-out . This could have been one of the factor which contributed to the crash

AERO - Boeing Assistance in Airplane Recovery

http://easa.europa.eu/system/files/d...ort_4-2011.pdf

Re: 8/8ths q -

With a mayday call and 7700 squawk you would see a distress phase in place immediately, would mean phonecalls being made, SAR launched, positions noted, and possibly involving nearby aircraft immediately to gather whatever information may help.

With loss of comms in my neck of the woods you are looking at an uncertainty phase within 15 mins of the unanswered call, then upgrading the phase as the situation deteriorates.

I dare say though that if this occurred in my FIR where the loss of comms coincided with loss of radar contact (and if shown to be true) aircraft not maintaining level, then you would jump straight to an alert phase..

From available information, a likely scenario is that the wreckage will be found not far from the last reported position - which if I understand things correctly was 24,000 feet altitude at 3°22'1.58"S 109°41'28"E and headed down at many thousand feet per minute. The plane would be expected to have gone below Indonesian primary radar's horizon at about that altitude. So this is about as good as it will get when it comes to knowing where a plane went down in the open ocean. Live satellite streaming of coordinates might not provide better resolution than what we have here.

On the first day's search there was rain and gail force winds at the surface and not many resources were available. No surprise it wasn't found. Yesterday the search was again mostly from the air and the water would have still been murky from the storm. So again, there's no surprise it wasn't found if the hull remained more or less intact limiting the amount of debris.

I suspect that today there will be ships searching the bottom with sonar in a 15 mile or so radius around 3°22'1.58"S 109°41'28"E and that will be how the wreck site will be found - unless miracle of miracles, the ULB functions as it is supposed to and a ship with a 37.5 kHz sonar receiver is available.

If this were a time of calm seas and sunshine, an aircraft would probably have spotted it by now in the 150 foot depths it rests in (this is world class scuba diving territory in good weather.)

There will be capable SAR ships on scene today. I'll be surprised if it isn't found today.

G-force depends on the specific location inside the airplane and on materials surrounding the object. If you have enough "padding" that braking from 270 kts to zero is spread over the distance of, say, 5 meters, mean g-force over this distance is merely 200G.

As for smartphones, they are usually not designed with shock tolerance in mind. They can fail in all sorts of easily preventable ways, usually with cosmetic damage. Devices which are designed for shock tolerance (so-called "rugged" devices) can handle a lot of stuff that would leave mass-market devices in shreds. A standard test for a rugged laptop/tablet is being able to withstand a drop from 4 foot height onto plywood-covered concrete onto any edge or corner without damage.

In reply to FlightDream111's post:

DRS Technologies, Inc. - Deployable Flight Incident Recorder Set (DFIRS)
http://www.drs.com/Products/C3A/PDF/DFIRS.pdf

Local media report sighting of about 10 pieces of debris resembling cabin door, emergency slide, 10-20km east of last known position. The debris was sighted from an airplane; a helicopter is now being dispatched to the site to assess further.

Probably nothing, but most hopeful lead so far.

https://s3.amazonaws.com/org.barkah..../Misc/door.jpg

Air Asia Indonesia Lost Contact from Surabaya to Singapore
 

Reports of debris 105nm from last position near South Borneo